Novel isodicentric chromosome 18 in an abnormal infant with a mosaic karyotype [46, XY/46,XY, -18,+ dic(18)(q12.2)]

Abstract
A previously unreported isodicentric chromosome 18 was discovered in an abnormal infant boy whose mosaic karyotype was 46, XY/46,XY,–18, + idic(18)(q12.2). His constellation of congenital anomalies was typical of the 18q‐syndrome. The clinical and cytogentic characteristics of this patient are reported, and the literature concerning isochromosomes of 18 is reviewed.